For both green and black varieties of peppercorn the peppercorn plant's berries (drupes) are harvested when the berry has not yet ripened. The berries still are hard, shiny, and green. While black peppercorns are blanched and sun-dried to darken their color and add pungency to their flavor, green peppercorns are processed to preserve this unripe color and the relative 'freshness' of their flavor.
The result is that green peppercorns are not as sharp nor as astringent in flavor, they are milder and can be eaten whole. In keeping with their preserved fruit nature, they are fresh, slightly tart and have a strong bolder and livelier aroma. Their delayed heat makes them a sometimes-substitute for chiles (remember capsicums are also fruit).
To use green peppercorns in a dish they can be crushed, milled, or even rehydrated. They work well in cream sauces, with fish or poultry, or with vegetables or more acidic foods.
Whole green peppercorns
More mild than black peppercorn, slightly tart. Delayed heat.
Lively, robust aroma
Small green berries with wrinkled skin
Can be used as a substitute for some non-smoky chiles. NOT a substitute for capers despite the similar appearance.
Use whole green peppercorns in cream sauces, or in fish or vegetable dishes.
You can rehydrate green peppercorn by putting them in a warm water bath for approximately 20-30 minutes.
Peppercorns are fruits! The wrinkled skin of green and black peppercorn is the skin of the fruit collapsing into the kernel as the fruit itself dries out.